The present invention relates generally to locking devices and, more particularly, to a locking device for use in locking a winged gas stop in the closed or "off" position.
Gas stops, or gas cocks as they are sometimes called, are very well known in the art and commonly used by gas companies for coupling a gas line to a house or other type of building. Gas stops usually include (1) a main body having an inlet port which is adapted to be connected to the main gas line and an outlet port which is adapted to be connected to the line leading into the house, (2) a plug inside the main body which is movable to either an open position wherein the gas can flow, a closed position wherein the flow of gas is blocked or positions in between, and (3) a knob on one end of the plug for use in physically turning the plug from one position to another. In one form of gas stop known as a "winged" gas stop, the main body and the knob each include a winged shaped portion having a hole. When the gas stop is in a closed position, the two wings and their respective holes are in alignment. The gas stop may be locked in that position when so desired by inserting some form of locking device through the two holes so that the wings cannot be moved relative to each other.
One form of locking device which has been used with winged gas stops comprises a barrel lock and an end cap. In using this type of locking device, the shank of the barrel lock is inserted through the two holes in the wings and locked on to the end cap which is positioned on the opposite side of the wings from which the barrel lock is inserted. The head of the barrel lock usually includes a small transverse circular hole which extends through the keyhole of the barrel and into which can be mounted a lead wire tamper indicating seal. Once mounted, if a key or other object is inserted into the keyhole the seal will be broken. One disadvantage of this type of locking device is that it can be tampered with without actually disturbing the seal on the head. Another disadvantage of this type of locking device is that it cannot be used with a bayonet type tamper indicating seal since this type of seal requires rectangular slots rather than a circular hole for mounting purposes.
Another form of locking device which has been used with winged gas stops comprises a shroud and a barrel lock. The shroud includes a metal shell which is shaped to fit over the two wings when the two wings are in alignment with each other. The shell is provided with a hole at the front end through which the barrel lock may be inserted and a locking member at the rear end onto which the tip of barrel lock containing the locking elements is brought into engagement with and then locked in place. Although the shroud covers the entire front end (i.e. shank) portion of the barrel lock and thus prevents tampering with the front end of the barrel lock, the device still suffers from the limitation that it is only useful with a lead wire type tamper indicating seal. Also, the head of the barrel lock is exposed and subject to attack. In order to overcome these disadvantages, shrouds have been constructed which include a sleeve at the front end into which the barrel lock is inserted. The sleeve includes apertures for use in mounting a bayonet type tamper indicating seal and at the same time encloses or covers the head of the barrel lock. In one version of such a device, the sleeve is integrally formed on the front of the shell. The disadvantage of this construction is that it is too costly to fabricate. In another version of such a device, the sleeve is formed as a separate element from flat stock and is resistance welded to the shell. After the sleeve attached, the unit is case hardened for strengthening purposes. One problem with this arrangement is that it is rather difficult to weld the sleeve to the shell in a satisfactory manner. Another problem with this arrangment is that the sleeve becomes rather brittle after the case hardening process and as a result is subject to breaking or being easily snapped off even before the device is actually used. Still another approach has involved forming a sleeve by boring a hole in a solid metal rod, forming seal receiving apertures in the rod and then attaching the rod to the front end of the shell by conventional welding. The disadvantages of this approach are that the apertures maust be formed by milling which is expensive, the cost in making the sleeve from solid bar stock is expensive and the welding operation itself is expensive.
Accordingly, the need exists for a new locking device of the type comprising a shroud having a sleeve containing apertures for mounting either a bayonet or lead wire type tamper indicating seal for use with a barrel lock in locking a winged gas stop in the closed position.